Three Polyhedron-Based Metal-Organic Frameworks Exhibiting Excellent Acetylene Selective Adsorption

Area of Science:

• Materials Science
• Chemical Engineering
• Separation Science

Background:

• Efficient separation of acetylene (C2H2) from ethylene (C2H4) and ethane (C2H6) is vital for producing high-purity C2H2 and recovering valuable gases.
• Polyhedron-based metal-organic frameworks (PMOFs) offer tunable pore sizes and spacious cavities, making them suitable for selective gas adsorption and separation.

Purpose of the Study:

• To investigate the relationship between the pore environment of selected PMOFs and their C2 adsorption and separation performance.
• To evaluate the efficacy of JLU-Liu22, JLU-Liu46, and In/Cu CBDA for C2H2/C2H4/C2H6 separation.

Main Methods:

• Selection and synthesis of V-type tetracarboxylic acid-based PMOFs (JLU-Liu22, JLU-Liu46, In/Cu CBDA).
• Adsorption and separation performance testing for C2H2, C2H4, and C2H6.
• Comparative structural analysis to correlate pore environment with adsorption behavior.

Main Results:

• JLU-Liu46 exhibited superior selectivity for C2H2/C2H4 (2.06) and C2H2/C2H6 (2.43).
• The enhanced performance of JLU-Liu46 is attributed to coordinatively unsaturated Cu sites and an optimal pore environment, including matched pore size, polarity, and a urea functional group.
• Transient breakthrough simulations confirmed JLU-Liu46's potential for ternary C2 gas separation.

Conclusions:

• The pore environment of PMOFs significantly influences C2 adsorption and separation efficiency.
• JLU-Liu46 demonstrates excellent potential for selective acetylene capture and separation.
• The synergistic effects of metal sites and framework characteristics are key to designing effective MOFs for gas separations.